Despite how it sounds, it is actually an adjective, used to describe something you like or to give approval.
As a noun, dopey sauce refers to an incredibly rare substance made from Nancy extract mixed with ginger ale. It is known for its aphrodisiacal properties and adds 69,420 points to your sassiness. May cause stomach upset in some people, causing you to postpone IKEA dates.
Childish or unnecessary terminology or dialogue people use in conversations to sound cute or funny. Some find it fun and play along, others find it sometimes condescending, rude, or superfluous altogether.
The most common dopey talk is in grocery stores by customers that joke around about prices of items, discounts, etc. As in, an item doesn't scan so it automatically becomes free.
Example 1 of dopey talk
*You enter the room with taco bell only to be eaten by yourself*